Demonstrators hit the streets in major cities across the country Friday — also known as May Day — to support workers rights, but many demonstrations also protested police brutality in the wake of Freddie Gray's death in Baltimore, and not all protested peacefully.
Here's the latest with what's happening across the U.S.:
Demonstrations turned violent in Seattle after night fell, with police reporting that protesters hurled rocks and wrenches at officers and damaged 25 vehicles. Police reported that an "explosive device" was thrown at officers, and a trash bin was pushed down a hill towards police.
Three officers were injured, two seriously enough that they were taken to a hospital, Seattle police said on Twitter. At least 16 people were arrested Friday night, police said.
"Tonight we saw assaults on police officers and senseless property damage, which cannot be tolerated," Seattle Mayor Ed Murray said in a statement. "Those who are violent will be arrested. We will work to disperse groups that are threatening the safety of our residents and businesses."
The march, which had been billed as an anti-capitalist demonstration, left Seattle Central College at around 6:30 p.m. local time, and rocks were thrown at police about an hour later, NBC station KING 5 reported. Officers responded with pepper spray.
Police used flash bangs and pepper spray to try and stop protesters from entering Interstate 5 about a half hour later, the station reported.
Earlier Friday, hundreds of people marched in Seattle during May Day demonstration for worker and immigrant rights, NBC station KING5 reported. Peaceful protesters at an event different from the one that led to clashes with police chanted"Seattle stands with Baltimore" and "All night all day, we will fight for Freddie Gray," according to the station.
The Seattle Department of Transportation said some streets were briefly closed and there were mass transit delays as marchers moved through Friday. An earlier "black lives matter" march attracted dozens of people.
A crowd estimated to be more than 1,000 in number marched in Manhattan Friday afternoon to "disarm the NYPD" after the death of Gray and other black men after encounters with the police.
"Cops are killing civilians on a regular basis, simple as that, and it's wrong," protester Jordan Jones told NBC New York. Almost 100 protesters were arrested Wednesday during protests over Freddie Gray's death. There was no immediate word of any arrests Friday.
Portland, Oregon, police used pepper spray on protesters who tried to march on a bridge Friday afternoon, NBC station KGW reported.
The confrontation occurred after some protesters broke away as hundreds marched on an approved route and tried to get onto the Burnside Bridge at around 4:30 p.m. local time (7:40 p.m. ET), the station reported. One person was reported sprayed.
The May Day protests were bolstered by a group calling itself "Don't Shoot Portland," which joined the main rally.
Students from Minneapolis Southwest High School began walking out of classes Friday morning holding banners and chanting, "No justice, no peace, prosecute the police," reported NBC affiliate KARE.
Dozens laid down at an intersection to stage a "die-in." The Minneapolis Public Schools supported the students' decision to exercise their rights and said they wouldn't be disciplined as long as they stayed peaceful.
Also, about 200 supporters gathered outside the Hennepin County Courthouse to support people who charged in connection with December's Mall of America "Black Lives Matter" demonstration, KARE said.
After tense demonstrations this week between protesters and police, people again hit the streets and gathered outside Oakland City Hall, They carried signs that read, "We stand with Baltimore," reported NBC Bay Area.
Protesters said they were not only rallying against police brutality but also speaking out about the high cost of living and wage disparity. An "Anti-Capitalist" rally was planned for Friday night at Latham Square in Oakland.
Demonstrations were reported to be smaller in the City of Brotherly Love Friday than the night before, when up to 800 people blocked traffic for hours and occasionally clashed with police in mostly-peaceful demonstrations. Thursday's protests were held in solidarity with the Baltimore.
Friday's protest, dubbed "TurnUp BMore" marched on City Hall as police followed on either side of the march, NBC Philadelphia reported. There were no reports of violence or arrests.